Lost spark after tune up

I have a 1976 starcraft with a 302 ford mercruiser. I just bought it aND took it out on the water. Ran great for a couple days then one day I pulled into a cover and it wouldn't start or fire at all. Checked for spark and it had nothing. Found out the coil had gotten water or something inside of it. I changed the coil and did a tune up with new cap, rotor and points. The engine had a bogging to it at wot so I figured I would clean the 2 bbl Rochester 2 jet carb also while I'm at it. Took it out after everything was replaced and it ran great. Still had a little bog to it though. I was cruising down the lake ando the boat just shut off and I realised it overheated. It will crank over but will not start. I have no spark again. I tested the new coil and have 1.6 between. The + and - and 8600 ohms between the center to both sides. I pulled the cap off the distributer and the plug from the coil to check the point for spark with a screw driver and see no spark. You can hear the buzzer when the key is on change noise when you break the points apart but there is no spark. I am stumped on what the problems are. There are a couple breakers but none were tripped. Any help would be greatly appreciated.

Why did it over heat?

Since you obviously have a voltmeter, what is the voltage from the moveable arm of the points to ground when open and also when closed ( ignition on )?

I honestly don't know why it overheated yet. I haven't looked that far into it. It ran perfectly fine all day until that point that it overheated and shut off on me. The move able arm on the points reads 12.2volts while open and .4 volts when closed.

you should have spark ... are you sure that the cam on the disti is opening the points? Did you set the dwell? IFSO, how?
Did you lube the cam w/grease when you replaced the points. If you don't do this, the "rubbing block" on the points will wear rapidly, and I do mean RAPIDLY, and the point gap will go to zero and no spark. (Don't ask me how I know....)

This is why I am so confused on why I do not have spark. I used the cam lube but I will say the inside of the distributor has a lot of rust dust. I cleaned out the best that I could but it seemed to gum up the cam lube. I hooked the volt meter up to the center of the coil and opened and closed the points and it is reading 12v. I know the voltmeter will not read what the spark should be but I didn't think it would read at 12v. I hooked up a spark tester to the center of the coil and when cranking no spark. Could my coil have failed and not creating a spark?

I figured out what had happened. A wire going to the coil had the coating rubbed off and it was grounding out. I also saw that the engine was about 25° out if time so this is probably the reason for the chug at wot. Thanks for the help